The present invention relates to a joint structure of a filtration apparatus and a filtration membrane module. More particularly, it relates to a joint structure for coupling a filtration membrane module to header pipes of a filtration apparatus.
When a large amount of crude water such as river water, lake/marsh water, underground water, sea water, secondary treated water of effluent and industrial waste water is filtered to remove turbidity, a plurality of filtration membrane modules are employed. In order to make water treatment systems compact, filtration membrane modules are generally arranged in parallel and linked to a main pipe, a so-called header pipe, of the filtration apparatus. Particularly, in the case of a long cylindrical filtration membrane module having hollow fiber membranes mounted therein, a plurality of modules are vertically arranged in parallel between the upper and lower header pipes of the filtration apparatus for use. Therefore, an enormous amount of labor has been required to do the work at high elevation to couple the filtration membrane module with high precision to the upper header pipe of the filtration apparatus.
A conventional joint structure for filtration membrane modules is exemplified in FIG. 7. FIG. 7 is a fragmentary front view illustrating the joint structure of one of the plural modules which are arranged in parallel in a vertical position between upper and lower header pipes 2, 3 and 4 of the filtration apparatus. Three openings of the filtration membrane module 1 are individually coupled to a branch pipe 2a diverging from the lower header pipe 2 and branch pipes 3a and 4a diverging from the upper header pipes 3 and 4, respectively, interposing connection components therebetween which are individually described below.
The conventional typical filtration membrane module comprises a filtration membrane (not shown), a casing 1a which mounts and secures the filtration membrane, cap nuts 5 fastened to the both ends of the casing, and coupling flanges 52. Each of the coupling flanges 52 is secured by the cap nut 5 which is screwed into and fastened to a thread groove formed at the end periphery of the casing 1a. 
The joint structure of the branch pipe 2a of the lower header pipe 2 and the lower opening of the filtration membrane module 1 in a vertical position is such that an O-ring 53 is interposed between a coupling flange 51 arranged at the upper end of the branch pipe 2a for supporting the weight of the filtration membrane module 1 and a coupling flange 52 secured at the end of the casing 1a of the filtration membrane module and said coupling flanges 51 and 52 are connected by a V-band clamp 54.
On the other hand, the joint structure of the branch pipe 3a of the upper header pipe 3 and the upper opening of the filtration membrane module 1 in a vertical position is such that the coupling flange 52 secured at the upper end of the casing 1a of the filtration membrane module and a coupling flange component 55 corresponding to said coupling flange 52 are connected by a V-band clamp 54 interposing an O-ring 53 therebetween, and further a pipe 55a arranged on the coupling flange component 55 and the branch pipe 3a diverging perpendicularly downward from the upper header pipe 3 are connected by a joint component.
Further, the joint structure of the branch pipe 4a of the header pipe 4 arranged approximately in parallel to the upper header pipe 3 of the filtration membrane module 1 and a third opening formed on the side of the upper end of said module 1 is such that the third opening is linked, interposing a flat packing 7, to an elbow 8, of which the other end is connected to a flexible tube 56 by a cap nut 6 screwed into and fastened to a thread groove formed at the end periphery of a conduit nozzle 1b arranged on the side of the end of the casing 1a, and further the elbow 8 is linked to a branch pipe 4a via a joint 57. The elbow 8 and the flexible tube 56 are linked by a cap nut 58 which is screwed into and fastened to a thread groove formed at the end periphery of the elbow 8.
Since such a conventional joint structure requires a large number of components for coupling the filtration membrane module 1 to each header pipe, difficulties have been encountered such that the work in assembling each of the connection components becomes troublesome, and in addition, the assembly work takes time. Further, in order to prevent liquid leakage at the connections of each component, high precision in assembly is required. Moreover, such a conventional system has the disadvantage of increased assembly labor and component costs.
The purpose of the present invention is to provide a joint structure which requires fewer components for connection, has a simple construction at connections, and does not cause any leakage. Also, the present invention provides a joint structure which requires reduced assembly labor, is set up by easy installation work, and is superior in installation reliability. Further, according to the present invention, a compact water treatment system can be constructed.
The present invention relates to a joint structure of a filtration apparatus and a filtration membrane module, wherein a cap with a pipe is coupled to at least one of the ends of the filtration membrane module by a cap nut capable of being screwed into a thread groove formed at the end periphery of the module, the pipe of the cap is inserted into and pressed against the one end of a joint capable of controlling connection length at the both ends, and a branch pipe of the header pipe of the filtration apparatus is inserted into and pressed against the other end of the joint.